We don't smoke cigarettes. 

I had a Section 8 tenant who smoked something in the bedroom (whether it was marijuana, cigarettes or something else, I don't know) and two of the walls had what looked to be watery light-colored tar running down the wall and so smoking does cause damage. 

Again whatever you feel comfortable with in terms of escalation here.No personal experience with this device and not sponsored, but I've looked into FreshAir Sensor previously for my Airbnb, and it is a simple plug and play device that detects cigarette smoke.

I clearly did have that part in my paperwork that one could not smoke in or on the property, and I saw massive butts on my porch and charred black marks where she put out her cigarettes on my cedar shake siding.

Our nightmare tenant also resulted in other tenant complaints, cops being called for noise, parking crazy in the parking lot taking up two spaces, destroyed carpets where they let cigarettes fall and burn on the carpet (and smoking wasn't allowed), her baby daddy moved in almost immediately - it can result in lots of time dealing with complaints and problems and I almost lost good tenants, too, who I had to assure I was getting rid of the nightmare tenants.  

I stopped eating out, I quit cigarettes, I educated myself, I cancelled memberships I wasn't using or could go without, I stopped buying clothes that would eventually end up in a donation bin, and I stopped sitting on the couch when I wasn't at my W2. 

She is on top of every tenant, knows what vehicle every tenant drives, knows when a tenant has visitors and for how long and she knows who smokes and throws their cigarette butts on the ground. 

Even if there is a little smoke smell left when you are finished, they won't notice over the cigarette smell on their clothes.

Maybe they were hoping I wouldn’t notice the bad smell permeating the house, or the unauthorized changes to the shower fixtures, missing closet shelves, mold/mildew on window sills and frames, filthy oven (all contrary to Lease), and also cigarette butts and dog waste outside (both required to be disposed of daily per the Lease)….well, you get the point.

What could make a deadbeat hillbilly happier that sitting on their fat butt; smoking a cigarette; working on a case of Bud; all of the while watching their 120 inch big screen TV - ALL PAID FOR BY THE TAXPAYERS?